The present invention relates to an apparatus and process for folding sheets of plastic material such as dough sheets.
The automatic folding of sheeted dough for stuffed bakery products is normally carried out on a continuous conveyor by the use of a type of plough equipment, and this method works well for small products such as pirogues. The plough-shaped apparatus is mounted above a conveyor belt carrying the dough products, and when a product passes beneath the plough, one half of its surface will be lifted and turned over to cover the other half. This principle is suitable if the dough product has a certain thickness and a surface of which is not too large to fold. However, for dough products with little self-stability, such as large sheets of dough having a width of above about 18 cm and a thickness of only about 1 mm, e.g., sheets of dough used for the preparation of Calzone pizzas, the plough method is not satisfactory, and for certain types of dough, it does not work at all. For instance, the half of the surface of the dough that is being lifted and turned collapses before it has covered the other half of the dough.
The methods so far proposed for folding dough sheets having a width above 18 cm involve complicated machinery and the folding precision is easily disturbed by small variations of the dough consistency.